Siemens circuit board model HC INTFC4-V6.3-S33A - HC Interface - Assy 5489906 - Schem 5489914 Rev. A - Fab 5489922 Rev. B. Used. Presumed good, however unable to test. This item was removed from a head/MLC (Multi-leaf Collimator) testing machine; please examine photos carefully to determine if it is the correct version for your equipment.